The present invention relates to a device that measures the launch conditions of an object. More particularly, the present invention is directed to a multi-shutter camera system for use with golf equipment. Further, the present invention is directed to a method of calculating the trajectory of an object based on the measured launch conditions.
Apparatus for measuring golf ball launch conditions are known as disclosed in U.S. Pat. Nos. 4,063,259; 4,375,887; 4,158,853; and 4,136,387. Techniques of detecting golf club head position and golf ball position shortly after impact using photoelectric means to trigger a flash to permit a photograph to be taken of the club head have been disclosed (U.S. Pat. Nos. 4,063,259 and 4,375,887). Golf ball or golf club head movement has been determined by placing reflective areas on a golf ball and using electro-optical sensors (U.S. Pat. No. 4,136,387). The electro-optical sensing of light sources on both the golfer""s body and club has also been disclosed in U.S. Pat. No. 4,137,566. In addition, apparatus for monitoring a golfer and the golf club being swung has also been disclosed (U.S. Pat. No. 4,137,566).
One particularly troublesome aspect of past systems for measuring golf ball launch conditions relates to their lack of portability. In this regard, prior systems have generally required cameras, sensors and strobe lights set up in various positions about the golfer. In addition, past systems have not had the ability to be utilized outdoors but have had to be set up indoors under less than ideal or realistic golfing conditions. As prior golf ball and/or golf club monitoring systems have not been portable and have not been capable of practical use outdoors, the systems have not been usable in the most desirable teaching or club fitting locations, e.g., on an outdoor driving range.
One additional area that has not been adequately addressed by past golf ball launch monitoring systems relates to the area of predicting flight path differences based on different physical characteristics of golf balls and/or different atmospheric conditions that a golfer may encounter after being tested by the launch monitor system. It would therefore be desirable to provide a system, which measures the launch or launch conditions of a golf ball having a particular construction, such as a two-piece construction, under ideal atmospheric conditions. Then provide the golfer with revised golf ball flight results based on computer predictions for golf balls having different physical characteristics (such as a three-piece golf ball) and different atmospheric conditions (such as higher elevations, higher humidity or more adverse wind conditions).
Other systems, even if portable, have required the use of a strobe light to take multiple images of the object on one frame. The strobe lights are used as shuttering means to freeze the object in a frame at several times. Also, at least three retro-reflective material markers are used on the object to provide reflection of light from the strobe light for the camera to take the images. The retro-reflective material markers, because of their thickness, may effect the results of the motion analysis for the golf ball. Furthermore, it is recommended that these markers are placed at precise locations on the object. This is labor intensive and difficult.
Therefore, an improved multi-shutter camera system is desired.
Broadly, the present invention comprises method and apparatus for measuring the speed, direction, spin and orientation of an object and from such data computing the launch conditions of the object.
In particular, the present invention contemplates a launch monitor system for measuring launch characteristics of a golf ball from data taken when the golf ball is in a predetermined field-of-view. The system preferably includes a light source and at least one camera unit having an electronic shutter. Unlike previous systems, the light source provides a source of light at least when the object is in the field-of-view. A strobe light is not needed to make an image as the electronic shutter replaces the strobe light. Further, because an electronic shutter and a non-flashing light source are used, retro-reflective material markers are not required.
In one embodiment, may include slide pads, wheels, or combinations of both. The support elements may be height-adjustable to vary the orientation and direction of view of the system and, specifically, the camera unit. As an additional aspect of the invention, a distance calibrator may be provided for calibrating the distance between the camera unit or units and the predetermined field-of-view.
Additionally, the present invention describes a method of calculating the trajectory of an object based on launch conditions measured while an object is moving in a predetermined field-of-view. Specifically, the method provides for taking at least one image of the object while it is in the field-of-view and calculating the launch conditions therefrom.